Semiconductor workpieces are processed within ion implantation systems. Ion implantation system may comprise an ion source, extraction electrodes, a mass analyzer, a collimating magnet, one or more deceleration stages and a process chamber. Throughout this disclosure, the term “housing” is used to refer to any chamber or other enclosure through which an ion beam passes. Thus, the housings include the deceleration stages, the mass analyzer, the collimating magnet and the process chamber. It is common for components disposed within these housings, such as the interior walls, electrodes, insulators and other equipment to show signs of contamination or become coated. This may be due to the deposition of ions or other materials on these components. In addition, the ions may tend to etch or corrode any material which is in the path of the ions, causing the flaking or sputtering of particulate. Some of this particulate may be deposited on the components in the housings. For example, components, such as bushings, cables, electrodes, lenses, and interior walls may become coated. These coating may become deleterious. For example, a coating may be more conductive than the underlaying component, thereby creating a conductive path where none previously existed.
Therefore, after a period of ion implantation system operation, this coating becomes deleterious, and must be removed. This is a common practice in this field and these coatings may be removed during a process known as a preventative maintenance (or “PM”) cycle. During the preventative maintenance cycle, each component may be cleaned in order to remove the coating. This process may be quite time consuming, as each component must be cleaned. This may result in unacceptable periods of time where the housings are inactive, which results in reduced throughput. In addition, the materials used to clean these components may be harsh, such that the underlying component is damaged by the cleaning material. Therefore, repeated exposure to these cleaning materials may also degrade the integrity of the component and lead to the need for component replacement.
In an attempt to minimize these periods of time and extend component lifetimes, in some scenarios, operators may stock a plurality of some of these components. In this way, during the PM cycle, the coated component is removed from the housing, and a clean component from the stock is used to replace it. The removed coated component can then be cleaned offline without negatively affecting the operation of the ion implantation system and returned to stock. While this method reduces the time required for the preventative maintenance cycle, it does require the operator to buy and stock additional components, some of which may be quite expensive. In addition, removal of these components may be non-trivial.
Therefore, a system and method of protecting components disposed within a housing from becoming coated would be beneficial. Furthermore, a method to minimize the time and cost associated with cleaning these components would also be beneficial.